Mechanical Vario

Must agree with Kirk on the quality of mechanical varios - I've not
flown a glider where the mechanical agrees with the electric! I
suspect that on a lot of gliders the mechanical, being the back-up,
doesn't get the TLC it needs to remain accurate (I'm sure they were
when new).

It may have been poor installation. If you run a pressure driven vario
on the same TE line as a flow driven, then you may get some funny read outs.

Master Martin

The three Tasman V1000 varios in our club have to be the most reliable
instruments we have. No moving parts, low power drain and they keep working down
to ludicrous voltages. You did not mention it but the LX is also worth considering.

In the club ships the mechanical varios get so battered they become less than
helpful. You can re-center them and calibrate them, but mechanical things
experience variation in manufacture and wear.

I keep a Winter mechanical vario in my personal aircraft partly because I have
had complete electrical failure in flight - and it is reassuring to have
something that pretty much works as long as there is airflow. But if I am honest
with myself, it is mainly because I hate holes in panels...

When I bought the aircraft it had a Westerboer WV5KB vario that did not co-exist
with the mechanical vario. Previous owner had installed restrictors and filters
and any number of kludges, that effectively meant that you had two instruments
that were pretty useless at all times. Removed the old electrical vario - it
came from the days when having "transistors" was an advertising point and was
wildly inaccurate.

A simple split of the TE line about 1m from the instrument panel (under the
seat) and the Tasman and Winter co-exist happily. Simple test using SeeYou to
analyse after noting the averages show that the Tasman is remarkably accurate.
Strangely the Tasman is often showing a lot more on the instantaneous readout
than the Winter. Presumably this is because of some degree of mechanical damping.

There are times when the mechanical sweep of the Winter can tell you things that
the electronic vario can't - we are very good at assimilating and assessing the
implications of movement. Conversely, I seldom use it because the audio is more
use centring, and the averager display tells me much more about whether to
persist. Once you go over to the dark side and start using the information the
electronic vario can provide to a flight computer or PDA there is no going back.

So - a modern solid state electronic vario is the way to go. If you need backup,
get one with a separate or internal battery. There is little chance that a
mechanical vario will be an improvement on that. Now if I could just convince
the wife that I really NEED another gadget, maybe a LX160, or a B400 would be
nice, and one o the club ships can have the Winter.

Bruce

Martin Gregorie wrote:
wrote:
On Sep 24, 5:54 am, wrote:
On Sep 23, 1:25 pm, Jeff Runciman
wrote:

This question was posted earlier but I was hoping for
a few more responses.
Do I put a mechanical vario or do I save space on the
panel.
Would love to hear what people have in their panel.
Jeff
Hi Jeff - The ILEC SB-9 is a 2 1/4" self-contained backup
vario with audio, and charges from the normal ship's power.
That's what I have as a backup in my Antares 20E, though this
glider has "more than adequate electrical power" available.

Best Regards, Dave "YO"

All I have is a Cambridge (I think) mechanical vario that i bought on
RAS. I did make up a TE prob a la dick johnson plans last winter and
it works as well as i could expect for a home made TE probe. Id love
to add audio, anyone know a cheap source?

eBay or other pilots replacing varios?

Seriously, I'd look for a used Borgelt B40 (its now replaced by the B400
but still fully supported by Borgelt) or a Tasman V1000 (used or new).
Both are relatively inexpensive. I've flown with and like both. The B40
has an internal battery for backup. The Tasman is pretty unbreakable
thanks to its LCD display. Both have an averager: you push a button on
the B40 to read average while the Tasman shows instantaneous and average
all the time. Both make nice noises.

the only other hole in my
panel is sized for the vintage crossfell vario that was in the glider
when i got it.

How big is a Crossfell?

Both the B40 and Tasman fit a 57mm (2 1/4") hole.

Owain Walters wrote:
I would always have a mechanical vario in my glider.
I use the electric (audio) as an indicator that I should
take a look at the far more accurate mechanical vario.

So, how do you know it is "far more accurate"? The mechanical varios I'm
familiar with change their calibration with altitude, but perhaps yours
doesn't?

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

snip
Another way of asking the question could be "who has ever had their
primary vario fail?"

snip

I have had the general Power failure version.

I have also had the Bubble Bee impaled on the pitot failure. Since my
primary vario is internally compensated this gave it some very strange
readings. Fortunatly my B40 is compensated by a TE Probe.

Brian
CFIIG/ASEL
HP16T N16VP

ILEC's are a bit more expensive, But I actually liked the Audio on it
better than the B40 I currently have.
The ILEC (SB-7) was my primary vario in my 1-26 and I loved it.

Brian
HP16T N16VP

On Sep 24, 9:18 am, wrote:
On Sep 24, 5:54 am, wrote:
Hi Jeff - The ILEC SB-9 is a 2 1/4" self-contained backup
vario with audio, and charges from the normal ship's power.
That's what I have as a backup in my Antares 20E, though this
glider has "more than adequate electrical power" available.

Best Regards, Dave "YO"

All I have is a Cambridge (I think) mechanical vario that i bought on
RAS. I did make up a TE prob a la dick johnson plans last winter and
it works as well as i could expect for a home made TE probe. Id love
to add audio, anyone know a cheap source? the only other hole in my
panel is sized for the vintage crossfell vario that was in the glider
when i got it. too bad it didnt work to well. it had a diaphragm TE
system and ran on a couple D cells.

Cambridge never made a mechanical vario, you are confused.

A homemade TE probe works on a Cherokee because, well, it
cannot really convert retained energy (ie, cannot do a high-speed
pass). On anything resembling a modern glider (say, a Blanik),
it is much less likely to work acceptably.

The vintage Crossfell should be fine for the Cherokee, even without
the TE diaphragm gizmo or proper TE probe...

Nothing against the Cherokee or other vintage equipment, but
its instrumentation needs are a bit different from what most
readers here fly...

Hope that helps clear up any confusion,
Best Regards, Dave

On Sep 24, 9:11 pm, wrote:
On Sep 24, 9:18 am, wrote:

On Sep 24, 5:54 am, wrote:
Hi Jeff - The ILEC SB-9 is a 2 1/4" self-contained backup
vario with audio, and charges from the normal ship's power.
That's what I have as a backup in my Antares 20E, though this
glider has "more than adequate electrical power" available.

Best Regards, Dave "YO"

All I have is a Cambridge (I think) mechanical vario that i bought on
RAS. I did make up a TE prob a la dick johnson plans last winter and
it works as well as i could expect for a home made TE probe. Id love
to add audio, anyone know a cheap source? the only other hole in my
panel is sized for the vintage crossfell vario that was in the glider
when i got it. too bad it didnt work to well. it had a diaphragm TE
system and ran on a couple D cells.

Cambridge never made a mechanical vario, you are confused.

A homemade TE probe works on a Cherokee because, well, it
cannot really convert retained energy (ie, cannot do a high-speed
pass). On anything resembling a modern glider (say, a Blanik),
it is much less likely to work acceptably.

The vintage Crossfell should be fine for the Cherokee, even without
the TE diaphragm gizmo or proper TE probe...

Nothing against the Cherokee or other vintage equipment, but
its instrumentation needs are a bit different from what most
readers here fly...

Hope that helps clear up any confusion,
Best Regards, Dave

I didnt know that there was any confusion. The more I thought about
it the more I realized that I have a Winter not a Cambridge. The
Crossfell did work OK but the scaling was off, like it never ever
showed more than 1 m/s and it would show down when I was going up.
Both of these issues may have been due to not enough voltage and
reversed polarity.

On Sep 25, 3:01 am, Owain Walters
wrote:
Because while the electric is flailing around the mechnical
gives indications that match what is happening with
a timed average.

So what you are saying is that you use your mechanical as an
averager. Which is fine, but doesn't say much for the accuracy of the
vario!

Whilst I agree electric varios are much better than
they used to be (I fly with a LX7000) I have always,
and still do, find that my mechanical gives a much
more 'real world' reading than an electric.

Which leads to an interesting point - it isn't so much the actual
reading on the vario that is important, as the ease of using the data
presented to climb more efficiently. So the whole "accuracy" argument
is a bit ridiculous. If it is really sensitive, it overreacts to
gusts. If it is highly damped, it's an averager. That's why I want
the audio, to let my brain (and butt) figure out the gusts from the
surges and center accordingly. Tough while staring at a needle on a
mechanical that hasn't been looked at much before, after the needle on
the ubervario MK 69 falls off...

To be fair, the altitude thing is rarely an issue where
I fly...!
Owain

I hear you! Nothing like setting off XC at 2000' agl to make you
appreciate a good vario.

Cheers,
Kirk
66

On Sep 25, 10:51 am, "kirk.stant" wrote:
....
Which leads to an interesting point - it isn't so much the actual
reading on the vario that is important, as the ease of using the data
presented to climb more efficiently. So the whole "accuracy" argument
is a bit ridiculous. If it is really sensitive, it overreacts to
gusts. If it is highly damped, it's an averager. That's why I want
the audio, to let my brain (and butt) figure out the gusts from the
surges and center accordingly. Tough while staring at a needle on a
mechanical that hasn't been looked at much before, after the needle on
the ubervario MK 69 falls off...
....
Cheers,
Kirk
66

One thing that bugs me about my mechanical (a winter) is that it
always over states the lift, which is important when deciding to take
a thermal or not. The damn thing generally tells me 6 knots, when it
is only 3-4 steady on the averager ! I need the re-paint the face
plate :-)

Todd Smith
3S

I hear you! Nothing like setting off XC at 2000' agl to make you
appreciate a good vario.

hmmm maybe thats what my problem has been this year